I know it's been a while (months) since the caption contest has been running, but now it's going again. It's simple: Click
here or go under Interactivity and click "Caption Contest". Then click on the set of red words under the first category (Open for Captions) and make funny/witty captions to go with the picture, while staying within site rules. Also rate the other captions. The top 20 (or all of them if there isn't at least 20) go to the final round which everyone votes on which caption is the best. This is done for every picture. So, yeah, click the red underlined "here" or go the other route and submit some captions (or not if you don't feel like it).